5TATL HORTICULTURAL COMMISSION 

LLLWOOD COOPER, Commissioner 



BUG V5. BUG 

Nature s Method of Controlling 
Injurious Species 



BY 



JOHN I5AAC 



Reprinted from the First Biennial Report of the 
State Horticultural Commissioner. 




5ACRAMLNTO 



W. W. SHANNON, 



1906 



5UPT. STATL PRINTING 



^ 



^^ 



n 



CALIFORNIA 5TATL COMMISSION OF HORTICULTURL. 



ELLWOOD COOPER 

JOHN ISAAC 

ED. M. EHRHORN.- 

E. K. CARNES 

O. E. BREMNER ... 
CHAS. T. PAINE.--. 



.Commissioner KSaiita Barbara 

Secretary San Francisco 

. Deputy M ou n tain View 

. Assistant Riverside 

Assistant Santa Rosa 

Assistant Redlands 



GERTRUDE BIRD Stenographer Sacramento 



OFFICE: 

Room 41, State Capitol, Sacramento. 

Branch Office, Room 11, Ferry Building, San Francisco. 



^Hn 



30 '^0: 



!^ BUG VS, BUG. 

By JOHN ISAAC. 



A somewhat siiuill and unpretentious exhibit was that made at the 
St. Louis Exposition by the California State Commissioner of Horti- 
culture, but it was one that attracted a great deal of attention, especially 
among scientific men and the more intelligent class of orchardists and 
farmers who visited that great exposition. This exhibit consisted of a 
very complete and well-arranged collection of the various insect friends 
to which California owes so much of her prosperity, and which are ever 
and continuously working in our interest. Many of these insects are 
exceedingly minute, so much so as to be practically out of the range of 
the naked eye. To overcome this difficulty they were displayed behind 
magnifying glasses of sufficient power to enable them to be seen, while 
descriptions of them and the work they are doing for our State were 
made in plain language. The result of this has been a great deal of 
inquiry from Eastern sources as to our beneficial insects and our Cali- 
fornia method of fighting bugs with bugs. To answer these inquiries, 
as well as to give our own people a wider knowledge of Avhat our insect 
friends are doing for us, the following pages have been prepared. 

Below is a list of the different insects exhibited at the St. Louis 
Exposition by this Commission : 

PREDACEOUS COCCINELLID^. 

Beneficial Insects. Host Insects. 

Vedalia cardinalis Cottony Cushion Scale (Icerya purchasi). 

Novius koebelei Cottony Cushion Scale (Icerya purchasi). 

Novius bellus Cottony Cushion Scale (Icerya purchasi). 

Vedalia sp. (black) . Cottony Cushion Scale (Icerya purchasi). 

Rhizobius ventralis -.- Black Scale (Saisseta oleoe). 

Rhizobius ventralis, larvcv.. -Black Scale (Saisseta olese). 

Orcus australasia Black Scale (Saisseta olete). 

Orcus chalybeus Yellow Scale (Chrysomphalus [Aspidiotus] citrinus). 

Rhizobius toowoombce. . . San Jk>se Scale (Aspidiotus perniciosus). 

Scymnus vagans Red Spider (Tetranychus telarius). 

Rhizobius debilis _ Various scale insects. 

Cryptolaemus montrouzieri .-Mealy Bugs (Pseudococcus [Dactylopius] sp.). 

Hyperaspis lateralis Cypress Mealy Bugs (Pseudococcus ryani). 

Exochomus pilatii Various scale insects. 

Chilocorus bivulnerus... San Jose Scale (Aspidiotus perniciosus), and others. 

Coccinella sanguinea Various scales and aphids. 

Coccinella californica .-.Various aphids. 

Coccinella abdominalis Various aphids. 

Coccinella oculata Various aphids. 

Hippodamia ambigua Various aphids. 

Hippodaniia convergens Various aphids. 



4 CALIFORNIA STATE HORTICULTURAL COMMISSION. 

PARASITIC HYMENOPTERA, DIPTERA, ETC. 

Beneficial Insects. Host Insects. 

Scutellista cyanea Black Scale (Saisseta olese). 

Dilophogaster californica . ...Black Scale (Saisseta olese). 
Hymencyrtus crawii ._--- ... Black Scale (Saisseta oleoe). 

Apheliiuis mytilaspidis Black Scale (Saisseta ole*). 

Aphelinus fuscipennis San Jos6 Scale (Aspidiotus perniciosus). • 

Aspidiotophagus citrinus.... Yellow Scale (Chrysomphalus [AspidiotusJ citrinus) and 

San Jos6 Scale (Aspidiotus perniciosus). 

Pteroraalus puparum Internal parasite of the Cabbage Buttertiy (Pieris rapa^). 

Comys fusca Brown Apricot Scale (Eulecanium armeniacum). 

Encyrtus flavus _ Soft Brown Scale (Lecanium [CoccusJ hesperidum). 

Coccophagus lecani Soft Brown Scale (Lecanium [Coccus] hesperidum). 

Coccophoctonus sp. ...Yellow and Red scales. 

Eupelmus mirabilis Internal parasite of the Katydid (Microcentrumretinervis). 

Braconid sp Parasite of Cutworm. 

Anastatus sp Egg parasite of Tent Caterpillar. 

Tachnia fly Internal parasite of Cabbage Butterfly (Pieris rapre). 

_ Internal parasite of Lecanium robinarum. 

Aphelinus sp. ... Internal parasite of Aphis. 

Somewhere about the year 1868, a California nurseryman in San 
Mateo County, not far from San Francisco, imported some lemon trees 
from Australia. There was nothing unusual about this, nor was there 
apparently anything unusual on the trees themselves; nevertheless 
that importation cost the State of California millions of dollars and 
came near destroying one of the most important of its fruit industries, 
for on those trees, unseen and unnoticed by any one, were some of the 
young of the now well-known cottony cushion scale (Icerya purchasi) . 
These soon reached their mature stage, and still no notice was taken of 
them ; they were regarded merely as a curious object when noticed, and 
it was never dreamed that they were the commencement of one of the 
most terrible pests that California fruit-growers have ever known. The 
insects increased in numbers, but not being in a fruit section, and their 
depredations being confined largely to ornamental stuff, they were dis- 
regarded. Soon afterwards a Los Angeles nurseryman and florist 
secured some of the imported stock, with the imported pest, and so it 
was introduced into Southern California. Here conditions were better 
suited to it than even in the section where it had first obtained a foot- 
ing in the State, and it spread much more rapidly. Soon it got into 
the orange orchards. Here conditions seemed perfect, and in a very 
short time it had spread to an alarming extent. Orchards in which it 
had become firmly established were covered with it until they looked 
as though they had been exposed to a severe snowstorm. It was soon 
found in remote sections, and in a short time appeared to have taken 
possession of the whole country. Nor did it confine itself to the orange 
trees; many varieties of fruit and a great quantity of ornamental 
plants fell beneath its attacks. It even found its way to forest trees, 
and for some time it looked as though it would reduce the whole countrj^ 



BUG VS. BUG. O 

to a desert. Orange-growers were in despair. From eight thousand 
carloads, shipments dropped to six hundred in one year. Every pos- 
sible remedy was tried, but none was found effective, and even the most 
costly served only to temporarily check the spread of the pest. Orange- 
growers were digging out and burning their trees to get rid of the pest, 
but even this did not avail, for had all the orhards been destroyed there 
was sufficient wild stuff' to keep it spreading. 

In 1888 the National Government made an appropriation for the 
purpose of advancing the American interests at the Melbourne Expo- 
sition, and the appointment of the late Hon. Frank McCoppin as 
chairman of the commission to forward said interests w^as the nucleus 
of California's first eff'ort in the search for natural enemies of orchard 
pests. McCoppin 's friends in the orange district where this pest had 
caused such terrible losses urged that he should do something to save 
the orange industry. Correspondence was opened with the Hon. 
Thomas F. Bayard, Secretary of State, and through him, with the 
Department of Agriculture and the Entomological Division of that 
Department. This resulted in the sending of Albert Koebele, who dis- 
covered the Vedalia cardinalis, with the commission. While there were 
others in the State who were convinced of the parasitic theory and 
enthusiastic in their eff'orts to bring about the investigation, there was no 
available money until the above opportunity presented itself. 

This discovery of a small ladybird known as the Vedalia cardinalis 
started California on her present course of fighting bugs with bugs, and 
no doubt this will continue until every insect pest that disturbs plant 
life and its fruits will be overcome by natural insect enemies, even if it 
should require traversing the very ends of the earth. 

It is to be hoped that other states, and the National Government, will 
take up this work and thereby save hundreds of millions of dollars' loss 
that is now borne by the cultivators of the soil. 

This ladybird was collected and forwarded to California and dis- 
tributed all over the State wherever the scale had made its appearance. 

Nearly, if not quite, all of the injurious pests of any section are intro- 
duced species, and in every case they have been introduced without their 
checks, for in its native habitat every pest, in fact every form of life, 
has some other form of life which preys upon it and prevents it from 
becoming redundant. Now, when any such form is removed to a new 
section, where it has no natural enemies, there is nothing to stop its 
unlimited spread, and as insects propagate more rapidly than any 
other form of animal life, without some check they would soon overrun 
everything within reach. These checks are usually other insects, and 
they are divided into two general classes— the predaceous class, or those 
which devour their prey from the outside, the most important among 
which is the great ladybird family, and the parasitic class, or those which 



6 CALIFORNIA STATE HORTICULTURAL COMMISSION. 

work in or on the body of their host. These latter are often microscopic, 
or very nearly microscopic, in size, but are among the most effective of 
our insect friends. 

Usually each predaceous or parasitic insect attacks but one kind of 
insect ; each has its own particular form of food and will touch no other. 
The Vedalia^ for instance, lives wholly upon the cottony cushion scale, 
and if it can not get this, it will starve before it will touch any other 
form of food; so that, in searching- for the enemies of our destructive^ 
insects, it is necessary to find just the right one. 

It is a fact well known to all entomologists, that in their native homes, 
while insects are sometimes very troublesome, and in some s^^ctions exiftt 
in unusual numbers, they never become the serious pests that they do 
when they are removed to a new country where their cheeks 'do not exist. 
Usually in their native homes they are rather rare than otherwise. So 
when it is known that any pest is especially severe in any section, as, for 
instance, the San Jose scale (Aspidiotus peruiciosus) over a great part 
of the Eastern States, it is very certain that it has been introduced there, 
and in order to find its check, we must find its native home, where it is 
scarce, and then we must find what agency is keeping it down. Some- 
times our native parasites will adapt themselves to the introduced 
species, as has been the case in California with the San Jose scale. This 
pest was as great a terror to our growers some twenty years ago as it now 
is over a great part of the Eastern States ; but one of our native parasites, 
ihe Aphelimis fuscipennis, adapted its taste to it, and finding in the San 
Jose scale a suitable food supply, it increased with almost unprecedented 
rapidity until it overtook the scale, and to-day this scale is no longer a 
pest in the California orchards. It is true that it occasionally makes its 
appearance in remote sections, but never to any dangerous extent, and 
the little parasite soon overtakes it and reduces it below the danger line. 
So little regard is paid to the San Jose scale in California now, that we 
never recommend any action against it. Spraying is still carried on, 
but this is more for the purpose of keeping the trees clean and healthy 
than for the purpose of getting rid of the San Jose scale. Before this 
parasite did such eit'ective Avork, California orchardists were having very 
much the same experience that their Eastern brethren are having now, 
and trees by thousands were dug out and destroyed in order to get rid 
of the scale. It is to be hoped that the days of this terrible pest in the 
Eastern orchards are numbered, for it has been discovered that the same 
parasite which hns freed the California orchards is now at work there, 
and in a report made by Prof. W. G. Johnson, when entomologist of 
Maryland, he says: 

Since we assumed chai-go of the State work in Maryland, we have collected the San 
Jose scale on various food plants and inclosed infested twigs, about four inches in 
length, in glass cylinder tubes, open at both ends ; the ends were closed with cotton, and 
if any parasites existed upon the scale, they were easily detected and mounted for 



BUG VS. BUG. 7 

study. Only upon rare occasions have we taken more than a half-dozen specimens 
from a single tube. This experience has been repeated year after year until the fall 
of 1899. • * * Last fall, however, I discovered a new locality for Aphelinus 
fuscipcnnis, near Easton, Talbot County, in an infested orchard along the Miles 
River. The orchard contained a miscellaneous variety of fruits, and all the trees 
were quite seriously infested with the San Jose scale. Instructions have been given 
the owner to cut them down as soon as possible and burn them. A quantity of small 
branches infested with scale were brought to the laboratory and inclosed in breeding 
tubes. Much to my surprise, these tubes were swarming with parasites a few days 
later. From one tube J, 114 specimens of Aphelinus fuftcipennis were taken, while 
a second tube gave 432. a third 1,478. and a fourth more than 1.000, but owing to 
an accident the count in the case last mentioned was not exact. 

The California method of fighting insect pests is to use the most 
efficient artificial means while we have to, and to this end we apply all 
sorts of known washes, dips, and fumigation, but, while so doing, we 
realize that these measures are very cumbersome, costly and inefficient, 
and that nature has provided a better way, and it is of this way that we 
avail ourselves. We endeavor to trace back the course traveled over by 
our destructive pests, to trail them to their native lair, and there we 
will find their check. This check, whether it be a parasitic or a preda- 
ceous insect, or both, as sometimes found, we secure, introduce, and 
breed, with the greatest care, in our insectary, where it becomes accli- 
mated in its new home, and as it propagates it is sent into those sections 
where the pest upon which it is to prey is most prevalent. This method 
has been found so effective that we have now very few really trouble- 
some orchard pests, the worst at the present time being the codling- 
moth, and for this we hope to find a natural check, and are now working 
toward that end. 

It must not be supposed from this that there are no insect pests in 
California. AVe have been importing these pests from all parts of the 
world for half a century past and have had representatives from all 
parts of the world, and have them still, for when an insect once obtains a 
foothold, its eradication is practically impossible, but by introducing its 
natural enemy, we offset one against the other, and give ourselves no 
further uneasiness as to the outcome. The pests may do some damage, 
they may break out in sections in unusual numbers for a time, but 
invariably they are reduced below the line of serious damage shortly 
by the natural means, and it is done more effectivelj^ and permanently 
than can be done by any artificial method. 

In an address before the fourteenth annual meeting of the Association 
of Economic Entomologists, Prof. C. L. Marlatt gave an account of a trip 
he had made to Japan and China in search of the native home of the 
San Jose scale, and in speaking of its discovery there he alluded to para- 
sites which he found working upon it, and which are the same species 
which have done such good work on this pest in California. He said: 

The apple industry of Japan is of recent origin, say within the last thirty years; 
most of the stock has been obtained from California, and as a rule was more or less 



EXPLANATION OF PLATE I. 

Fig. 1. Novius Iwebelei, Olliff; Koebele's ladybird. Male; enlarged, 

la. Novius koehelei. Male ; natural size. 

Ih. Novius koehelei. Female; natural size. 

Ic. Novius koehelei. Larva; enlarged. 

2. ^' Black Vedalia." Enlarged. 

3. Novius hellus. Beautiful ladybird; enlarged. 

4. Novius (Vedalia) cardinalis, Mulsant; Australian ladybird; 
4a. Novius {Vedalia) cardinalis. Natural size. 

4&. Novius (Vedalia) cardinalis. Larva ; enlarged. 

5. Lestophonus icerya. Dipterous parasite of the cottony cushion 

scale; enlarged. 
5a. Lestophonus icerya. Natural size. 

6. Ophilosia crawfordi. Hymenopterous parasite of the cottony 

cushion scale; enlarged. 
6a. Ophilosia crawfordi. Natural size. 

7. Twig infested with cottony cushion scale ; natural size. 
7a. Icerya purchasi crawii, Cockerell. 

Ih. Icerya purchasi maskelli. 



California State Commission 
OF Horticulture.. 



PLATE I 




BUG VS BUG. 



Ti-iK eeneficij^l iri sects 

THAT SAVEE) THE 
CITRUS FR-JIT Ii\^DUSTR-l- Or CALIFORNiA. 



BUG VS. BUG. 9 

infested with San Jose scale when received. Throughout this region the San Jose 
scale was found scatteringly in all orchards and in all gardens. In Aomori and 
vicinity it is doing no very great damage in any of the orchards, but in some of the 
small gardens and especially in one or two neglected ones in the city of Aomori, it 
was as abundant on particular trees as it often is in America. At the first investi- 
gation no evidence of parasitism was seen, but from later collections two of the 
parasites which attack the scale insect in America were raised in great numbers from 
infested branches collected at Aomori. These as determined by Dr. Howard are 
ApheliriHS fnscipcnni.'i, How., and Aspidiotophogus citriniis. Craw, the latter being 
the more numerous. 

This latter parasite is the true internal parasite of the Japanese 
yellow orange scale. The San Jose scale is not a native of Japan, so it 
is evident that this little parasite adapts itself to the introduced variety, 
which is a near relative of the yellow scale upon which it is generally 
found. 

So effective has this work of introducing beneficial insects and encour- 
aging native parasites been, that we have practically reduced all the 
worst of our scale pests and very many other destructive insects below 
the danger line. Among the many beneficial insects which are now at 
work in our State, and the pests which they are at work upon, and most 
of which they keep in control, we name the following : 

COCCINELLID^. 
Vedalia eardinalis, Mulsant. (Plate I, Figs. 4, id, if>.) This is 
connnonly known as the "Australian ladybird," from the fact that it 
was imported from Australia in order to work upon the cottony cushion 
scale (Icerya purclum, Maskell). As stated above, this pest had 
obtained such a foothold in our orange orchards that the citrus industry 
of California was threatened. The fact that the cottony cushion scale 
came from Australia, where it was not a pest, was sufficient proof that 
there was some \Qvy efficient check at work upon it there, and investiga- 
tion by Albert Koebele discovered this little beetle. The orange-growers 
of Los Angeles County, especially, had a very expensive experience with 
this scale. As it had spread into the wild bushes and trees, extermina- 
tion by artificial means was out of the question. Now the scale is no 
longer a pest. When it appears in an orchard the owner is supplied 
with a colony of Vedalia. During the summer the transformations of 
this ladybird are very rapid. From the q^^, through the larva and 
chrysalis, to the perfect beetle, takes only twenty-one days. Of course, 
the larvae are the most active feeders. AVhen short of feed, the larvae 
will attack each other, but no matter how^ hungry they are they will not 
eat any other species than the cottony cushion scale. This ladybird 
breeds throughout the year. 

Novius koebelei, Olliff (Koebele's ladybird). (Plate I, Figs. 1, la, 
lb, Ic.) This is another effective enemy of the cottony cushion scale 

2— BII 



20 CALIFORNIA STATE HORTICULTURAL COMMISSION. 

and does as good work as the Vedalia. The latter, however, was first 
introduced, and its reputation became so great that all others were over- 
shadowed by it. The Novius koehelei, hoAvever, has proved itself equally 
as prolific and quite as voracious a devourer of the cottony cushion 
scale as its companion. This ladybird is also an introduced species, 
having been sent from Australia for the State Board of Horticulture 
by Mr. Koebele on his second trip to that country. 

The illustrations give a good idea of this beautiful and active little 
ladybird. It feeds upon the cottony cushion scale {Icerya purchasi), 
searching out the solitary scales even better than the Vedalia. It passes 
through its different stages in about the same time as the latter. 




FIG. 1. Xovius kot'bek'i, mak', enhirSLMl. FIG. 2. Novius koebelei, female, enlarged. 



Novius bellus (Beautiful ladybird). (Plate I, Fig. 8.) This is also 
an Australian species, having been introduced into California from that 
country by Mr. George Compere. It is one of the several coccinellid 
enemies of the cottony cushion scale, and has done very excellent work 
upon that pest. It has been generally distributed over the State. 

Vedalia sp. (Plate I, Fig. 2.) This is an unnamed species of Vedalia, 
from its color commonly known as the "Black Vedalia." It is also an 
Australian species, introduced by the State Board of Horticulture 
through Mr. George Compere, and is another of the coccinellids which 
prey upon the cottony cushion scale. 

Rhizobius ventpalis (Black ladybird). (Plate IV, Figs. 3, 3a, 86.) 
This is also an Australian ladybird, introduced by the State Board of 
Horticulture through Mr. Koebele, and is one of the natural enemies of 
the black scale {Saisseta [Lecanium] oleae) . This ladybird was intro- 
duced for work on tlie black scale, and was generally distributed by 
the State Board of Horticulture wherever that pest Avas found. It was 
one of the most promising of the many importations of beneficial insects 
and took hold of its work with a vigor that gave promise of soon extir- 
pating one of the worst of the California scale insects. Wherever it was 
introduced in the coast counties of the State, it increased with wonderful 



BUG VS. BUG. 



11 



rapidity and the scale as rapidly disappeared, and in those sections it 
j^till continues to do good work, but efforts to establish it in the interior 
counties have not met with as good success, the heat probably being too 
intense for the young larvie. This insect, however, is well established 
all over the State, and in many sections is as abundant as any of our 
native species. Wherever it is abundant, it is a chief factor in keeping 

in check the destructive black scale. 

• 

Opcus austpalasia, Boisd. (Six-spotted blue ladybird). (Fig. 3.) 
This is one of the most beautiful of the introduced species. Like most 






Obcos austhalasi/C. Boisd 
2 Pupa enveloped in la 



FIG. 8. Orc-us australasia. 

of the latter, it is a native of Australia, and was imported from that 
country by the State Board of Horticulture through Mr. Koebele. It is 
an enemy of the black scale (Saisseta [Lecanium] oleae) , and is now 
well established in many parts of California, especially in the coast 
counties. The female is nearly one fourth of an inch in length, deep 
blue in color, with six orange red spots on the wing-covers. The male 
is similarly marked, but is a smaller insect. This species is a more 
general feeder than 0. cJialyheus. In Santa Barbara 
County it is bred on black scale, and in Alameda on the 
pernicious scale. It loves the sunshine, and is found 
more numerous toward the top and the outside branches 
of the trees in which it is established. The larva -aiid 
pupa resemble the same stages of Pilate's ladybird. 

Opcus ehalybeus, Boisd. (Steel-blue ladybird). (Fig. 
4.) So named from its brilliant steel-blue color, which 
makes it a conspicuous object wherever it is found. This 
ladybird preys largely upon the yellow scale {Chrysoni- 
phalus [Aspidiofiis] ciiriniis, Coquillett), and also upon bens, enlarged. ^ 
the red scale (Chrysornphalus [Aspidiotus] aurantii, Maskell), which 
it consumes in great quantities. This was introduced into California 




EXPLANATION OF PLATE 11. 

Fig. 1. Encyrtus flaviis, Howard. Enlarged. 
la. Encyrtus flaws. Natural size. 

2. Coccophagus lecani, Howard. Enlarged. 
2a. Coccophagus leca^ii. Natural size. 

3. Comys fusca, Howard. Enlarged. 
8a. Comys fusca. Natural size. 

4. Soft brown scale {Coccus [Lecanium] hesperidum, Linn.). 

On orange leaf. 

5. Brown apricot scale {Eulecanium [Lecanium] armeniacum, 

Craw). On prune twig. 

6. BroAvn apricot scale, showing exit holes of Comys fusca. 



California State Commission 
OF Horticulture. 



PLATE II 




BUG VS BUG. 

THE INTEHTIA:- P.^J?ASrTES THAT HOLD IN CKECi 

THE "soft BR-OWri SCALE" AJvEi THE 

"BROWN APRICOT SCALe' IIj CATTFOP.niA 



BUG VS. BIG. l:^ 

by the State Board of Horticulture some years ago and is now found 
established in many parts of the State. 

Rhizobius (toowoombse) lopantha. (Plate III, Fig. (>.) This little 
ladybird was formerlj^ described under the name of Scymmis margini- 
collis, but is identical with Rhizohius lopantha. Mr. Koebele sent this 
beetle about the same time that he introduced the Vedalia, but it wa.s 
found in the State previous to that. However, it has only been within 
the past few years that its value has been observed. It breeds from 
early spring until late in the fall. As comparcfl with the beetles the 
larvce are very large, they are light colored, with a lighter oblong scjuare 
on center of the back, and remain a long time in the larval stage, feed- 
ing voraciously. AVhen about to change to the chrysalis, they hide 
away under cobwebs, dry leaves, and other debris. The beetle is 
metallic black, with a brown thorax. They feed on Aspidiotus perni- 
ciosus, Chrysoniplialus (Aspidiotus) aurantii, Clirysompkalus (Aspidio- 
tus) citrinus. Aspidiotus hederae (nerii) , and occasionally on aphis. 
In San Diego County it is proving effective on purple .scale (Lepidosa- 
plies hechii). In alluding to the excellent work of this little beetle on 
the purple scale in the above named county, Mr. Allen, of Bonita. 
Avrites : 

With us the largest hatch of purple scale has usually been in May. So far this 
year I have not seen a single instance of purple scale hatching, nor can I find any 
live scale in an orchard adjoining us. every tree of which a year ago was literally 
alive with them. Since last .July this orchard has been to my knowledge thoroughly 
stocked with the Scynuius. though when they first entered it I can not say. As they 
undoubtedly came in large numbers their work has been rapid. 

, I sprayed only a small part of the ranch last summer, and there can be no question 
but that, except for the work of this parasite, our place would be teeming with the 
purple scale, whereas T have yet to see the first live one, and our fruit, from trees 
that used to be infested, is now coming off the tree clean. I believe this ladybird is 
also eating the yellow scale, because there is so much less of it on the fruit, but of 
this I am not yet sure. 

By September the efficiency of the purple scale parasite should be thoroughly estab- 
lished, for if any live eggs are left thej' must hatch before that time ; yet even now it 
seems to me that the work of the i^cymnns is second only to that of the Vedalin. and, 
considering the difference of the scales and the fact that the purple is so heavily 
armored, its work seems even moi'e remarkable. 

Seymnus vagans. This is one of the smallest of the ladybird 
family, but not one of the least important. It is an enemy of the red 
spider pest which is very general all over the world, and especially 
detrimental to almonds, prunes, and citrus trees. The long, dry seasons 
of California are favorable to the spread of this pest, which flourishes 
under arid conditions, and which has been especially troublesome here. 

This little ladybird was introduced from Australia by Mr. George 
Compere for the State Board of Horticulture. It was found to be veiy 
effective in checking the spread of the pest, and has been generally 
established in California. 



14 



CALIFORNIA STATE PIORTICULTURAL COMMISSION. 



Rhizobius debelis. This is another one of the introduced species of 
ladybirds which we owe to Australia. It is a scale-feeder and has been 
very generally distributed in the State. 

Cryptolgemus montrouzepi. (Fig. 5.) This is another of the Austra- 
lian coccinellidse. It is the natural enemy 
of the mealy bug {Pseudococcus [Dactylo- 
pius]). It has been introduced into the 
Hawaiian Islands, where this pest was so 
bad in the coffee plantations as to almost 
threaten the total destruction of the crop, 
and it has done such good work that the 
pest has been practically cleaned out. Suc- 
cessful efforts have also been made to estab- 
lish it in the coffee plantations of Centi'al 
America, where the mealy bug has also ap- 
peared in destructive numbers. 




FIG 



Cryptokumus inontrouzeri. 
eiihirge<l. 



Hyperaspis lateralis, Mulsant. This is one of our native ladybirds 
and is very generally distributed over the State. It is a small, black 
ladybird, with two reddish-yellow spots on the elytra, near the apex, 
two spots on the disc, and two blotches of the same color on the for- 
ward lateral margins. Forehead and edge of thorax yellow. Feeds on 
pernicious scale in the adult form. Cypress trees {Cupressus macro- 
carpa) in the suburbs of San Francisco that were seriously infested 
with the cypress mealy bug {Pseudococcus [Dactylopius] ryani) were 
cleared of the pest by this ladybird. The larvae of this species are 
covered with a cottony secretion and resemble mealy bugs. 



Exoehomus pilati, Mulsant. (Fig. 6.) This is ano 
common native ladybirds. It resembles in 
general appearance the twice-stabbed lady- 
bird (CJiiloconis [hiv'ulnerus] f rat emus) , 
but is much larger. It also differs from the 
latter in having the under side of the ex- 
tremity of the abdomen black, instead of red. 
The larvae resemble the twice-stabbed, but 
are larger and lighter-colored. Both the 
larva and beetle feed upon young black scale, but the\ 
very rapidly. 



ther of our verv 




FIG. c. 



do not 



Chiloeopus (bivulnerus) fraternus (Twice-stabbed ladybird). (Plate 
III, Figs. 3, 3a.) This is one of our most important native ladybirds. 
The larvai are most voracious, and destroy great numbers of young 
i)lack, pernicious, and other scales. The younir are long and covered 



BUG VS. BUG. 15 

with dark spines, crossed with a yellowish band near the middle. 
"When about to change into the pupa or chrysalis, the larva selects the 
under side of the large branches, where it attaches itself with a gummy 
substance to the bark, head downward. In a few days the spiny, larval 
skin splits longitudinally, exposing the inclosed chrysalis. When the 
beetle issues from the chrysalis it has a black head, with white wing- 
covers ; in a short time this changes to a shiny black, with a red spot 
on each elytra. In this stage it also preys upon scale insects. 

Coecinella sanguinea, Linn. (Blood-red ladybird). This is a medium- 
sized native species, found very generally distributed over California. 
It feeds upon aphids and young scale insects, but is not so common as 
some of the other species, and is not, therefore, so beneficial. The 
beetle is of a solid c*olor, varying in intensity from a dull red to a bright 
scarlet. 

Coecinella ealiforniea, Mann. This species is a very common one in 
this State, and the beetles are sometimes found in enormous numbers. 
They are very social in their habits, and can sometimes be found in 
such numbers as to be gathered by quarts. They are larger than the 
sanguinea. The elytra are orange-red, without spots or markings; 
thorax is black, with a light spot on each side. They feed principally 
on aphids. Like other species of ladybirds, the larvee do the most good. 

Coeeinella abdominalis, Say. This is known as the "ashy gray 
ladybird," from its prevailing color. This ladybird is hemispherical in 
form, ashy gray in color; with seven small black spots on the thorax 
and eight on each wing-cover. It is said to be one form of Coecinella 
oculata. Say. It is an aphis-feeder, and where it exists in quantity does 
good work. 

Coeeinella oeulata, Say (Eyed ladybird). This, while it is supposed 
to be one form of the preceding, does not resemble it in any manner, in 
its markings or general appearance. The adult insect is deep black in 
color, with two distinct orange-red spots on the wing-covers, and might 
easily be mistaken for Chilocorus fraternus. There is a distinct differ- 
ence in these two insects in the markings of the thorax, the oeulata 
being light yellow on the under side and around the margin of the 
thorax. Like its other form, abdominalis, it is an aphis-feeder, and a 
very effective one Avhere it is found ; but in this form it is not a common 
insect in this State. 

Hippodamia eonvergens, Guer. This is another of the common 
ladybirds of California, and is found throughout the State during the 
summer months very plentifully, among corn and other vegetables. 
The larv-a? feed upon aphids and other insects, while the mature insects 



EXPLANATION OF PLATE III. 

Fig. 1. AspidiotopJiagus citrinus. Craw. Enlarged. 

la. Aspidiotophagns citrinus. Natural size. 

2. Aphelimis fitscipennis, Howard. Enlarged. 
2a. Aplielinus fuscipennis. Natural .size. 

3. 0/ii7oco>-H6' ^ifiiiiients*,- "twice-stabbed ladybird. " Natural size. 
3a. Chilocorus hivulnerus. Larva. Natural size. 

4. San Jose scale (Aspiodiotus perniciosus, Comstoek). Natural 

size. On pear twig. 

5. Yellow .scale {Aspidiotus citrinus, Coquillett). Natural size. 

On orange leaf. 

6. Rhizohius (toowoomhae) lopantha. Natural size. 



California State Commission 
OF Horticulture. 



PLATE 




# 




i^iTH.BRTTTPM ^HEV.BV. 



BUG VS BUG. 



THE FOUR SPECIES OF INSECTS THAT SUBDUED THE 
"SAN ^OSE SCALK" i^j^D "YELLOW SCALe" 

IN CALIFORNIA. 



BUG VS. BUG. 



17 



also feed upon aphids, young- scale, etc. The beetles vary somewhat in 
color; some are of a deep red, while others are of a dull browm, the 
markings, however, being uniform. Sometimes after ripe fruit has been 
punctured by birds or other agencies, the beetles of this species will be 
found upon it, sipping the moisture, and on this account they have been 
thought sometimes to be injurious. They are, however, among the most 
important of our insect friends. 

Hippodamia ambigua, Le Conte. (Figs. 7, 8, 9.) This is a very 
abundant native species. The adult beetle resembles the blood-red 
ladybird somewhat, but is narrow^er in proportion to its leng:th, and 
flatter. It is distributed over the w^hole State, and is often found in 
great numbers. It is an aphis enemy, and does' excellent work on the 
plum, apple, and woolly aphis. During the later fall months these 
insects may often be found in sheltered places in great masses, in 
which condition thev hibernate during: the colder months. 




FIG. 



Hippodamia ambigua. 
enlarged. 






FJU. 8. Hippodamia ambigua, 
pupa. 




FIG. 9. Hippodamia ambigua, 
•a. 



Eippoda 
larvi 



HYMENOPTERA. 
Seutellista eyanea, Motsch. (Plate IV, Figs. 1, la, 16, Ic.) This 
IS comparatively a new introduction into our State, having been secured 
from South Africa, where it was found to be a very effective worker on 
the black scale (Saisseta oleae) . In the short time it has been estab- 
lished among us. it has done most remarkable work, and, so far, promises 
to be as efficient a check for the black scale as the Vedalia has been on 
the cottonv cushion scale. Of its introduction, ^Tr. Craw writes : 



It was not until Prof. Charles P. Lounsbury, Government Entomologist of Cape 
Colony, called attention to the l^cutellista eyanea as an efficient enemy of the black 
scale in that country, that its true value was recognized. 

Through the efforts of the Hon. !<i. F. Leib, of San .Jose, and iNIr. Ed. :M. Ehrhorn, 
of Mountain View, Senator Perkins appealed to the United States Department of 
Agriculture to use its good offices toward securing this valuable insect. Several 
colonies were forwarded to Mr. Ehrhorn, but. unfortunately, without any practical 
results from either sending. On October 1, 1901, Professor Lounsbury wrote me : 

"By to-morrow's boat we start you two boxes containing cuttings of oleander 
bearing parasitized scale. It is not ideal material by any means, and this is not the 
season we most wish to send in, but the scale and its parasites are both so scarce 
that we must send what we find as soon as we find it. Most of the scale in your 



18 



CALIFORNIA STATE HORTICULTURAL COMMISSION. 



^ icinity will be old by the time this reaches you, but I am in hopes that you may be 
able to get material from the south of the State that will take a generation of the 
parasite. Owing to the probable presence of secondary parasites, it is, of course, 
inadvisable to send the original material to any orchardist down there." 

From this sending, seventeen perfect insects developed, of which four were females. 
When placed in a breeding case, a small spider that was hidden in a rolled-up leaf 
seized and killed one of the females, leaving us but three from which to colonize the 

State. 

On December 26, 1901, I examined a full-grown black scale from the tree in the 
breeding case, and found a small maggot of the SGutellista cyanca, about twice the 
size of a black scale egg. This convinced me that they were breeding, so no further 
examination was made. On February 7, 1902, the parasites began to issue from the 
scales. During the warm summer months we found that the ^cutelUsta passed 
through all its metamorphoses in forty-seven days. 

Colonies have been sent to all the counties of the State where black scale has been 
troublesome. From personal examination and from material sent in, it is evident 
that the parasites have obtained a good start, and the coming season will, we hope, 
see them thoroughly disseminated. 



Description: In the female, the antenna; are reddish-brown, with 
the ring joints and hips dark and more spreading than in the male. 
The antenna of the male are black from the ring joints to and including 




FIG. 10. 



Tomocera californifa, male, greatly 
eiilariied. 



FIG. 11. Tomocera californica, female, greatly 
enlarged. 



the clubs, with the scape reddish-brown ; the legs in both sexes are black, 
lai'vsi reddish-brown, and claws black; the scutelluni in both male and 
female is very large. As the flies are small and very active, it is diffi- 
cult to detect them on the tree upon which they may be placed, and the 
best way to determine if they are established, is to remove and examine 
the inside of the full-grown scales about forty to forty-five days after 
liberating the parasites. The larva is maggot-shaped and white, this 
soon changing to the pupa, which is black just before changing to the 
perfect fly. 



Tomoeepa (Dilophogaster) ealifopniea, Howard. (Figs. 10, 11). This 
is one of our native internal parasites. In has been one of the most 
effective checks of the black scale in the State, but was not able to keep 



BUG VS. BUG. 



19 



this pest wholly under control. In a report on scale insects and their 
parasites, Professor Comstock says of this insect : 

This is one of the most interesting parasites, both structurally and economically, 
which we have discussed in this paper. It lives upon the destructive black scale, and 
so abundant is it in certain regions that upon more than one tree at least seventy-five 
per cent of the scales appeared to be parasitized. In no locality was the black scale 
found without this attendant destroyer. 

The female parasite pierces the body of the female bark-louse and deposits probably 
but a single egg. At all events but a single parasitic larva has ever been found upon 
a single scale. The larva of the parasite feeds upon the eggs and the young of the 
Lecanmm, and, also, later upon the mother herself. When full grown it is about 0.15 
inch long, broad, spindle-shaped, somewhat more pointed at the anterior than at the 
posterior end of the body. Its color is clear white, the contents of the alimentary 
canal, however, often showing through and giving it a blackish tinge. This larva 
transforms to a whitish pupa, which soon turns black. The adult parasite makes 
its exit through a round hole which it cuts in the back of the scale. 

Hymencyrtus erawii, Aslmiead. This is an Australian insect, and 
is one of the ver}^ effective internal parasites of the black scale in that 
country. It was introduced into California by Mr. George Compere, 
and has been reported as doing verj^ good work in the districts where it 
has liecome established. 




FKi. 



Aspidiotophagus citrinus, greatly 
enlnrged. 



Aspidiotophagrus citrinus, Craw. (Plate III, Figs. 1 , 1^/. See Fig. 12.) 
The internal parasite of the yel- 
low scale {Chrysomphalus [As- 
pidiotus] citrinus) and the San 
Jose scale {Aspidiotus pernici- 
osus). The former scale was at 
one time as great a source of 
trouble to the orange-growers of 
southern California as the red 
scale (Chrysomphalus [Aspid- 
iotus] aurantii) is now. It fairly 
covered the citrus trees, reduced 
the quantity of fruit, and destroyed its quality. Every effort was made 
by artificial means to resist its attacks, but these were unavailing. 
Finally it was discovered that there was some natural check at work, 
and investigation discovered this little internal parasite. Instructions 
were at once given to the orange-growers to stop spraying for the yellow 
scale and to give this little friend a chance to increase. This advice 
was followed, and in a very short time the yellow scale disappeared 
from that section and it has not since been regarded as a pest, although 
no other means have been taken to check it. Mr. Craw has bred this 
parasite from yellow scale upon imported trees from Japan. Mr. Mar- 
latt bred it in numbers from San Jose scale in Japan. It is also one of 
our best checks for the same scale in California. 



EXPLANATION OF PLATE IV. 

Fig. 1. Scutellista cyanea. Motsch. Female: enlarged. 
la. Scutellista cyanea. Natural size. 
1&. Scutellista cyanea. Larva; natural size. 
2. Scutellista cyanea. Male; enlarged. 

8. Rhizohius ventralis, Blackburn. Black ladybird; enlarged. 
3a. RJiizohiiis ventralis. Natural size. 
3?>. Bhizohius ventralis. Larva; enlarged. 

4. ''Black Scale" (Saisseta [Lecannmi] oleae, B^vn) . On orange 

twig. 

5. "Black Smut"; fungus, existing on exudation of black scale. 

6. "Black Scale," showing exit holes of Scutellista cyanea. 



California State Commission 
OF Horticulture. 



PLATE 




I h 






BUG VS BUG. 

THE TRUE PARASITE Ar^lD ENEMY 

OF THE 

" B LAC K. S C ALE . 



BUG VS. BUG. 2.1 

Aphelinus fuseipennis, Howard. (Plate III, Figs. 2, 2a.) It is Avell 
within the niemory of the fruit- growers of California when the San Jose 
scale was the most terrible of our pests. It antedated the appearance of 
the cottony cushion scale and attacked nearly all of our deciduous fruit 
trees. For some time it seemed as^though the fruit industry of our State 
Avas doomed, at least such varieties as were attacked by this pest, and 
orchardists were digging out and destroying their trees by thousands in 
order to stay its ravages. Various compounds were devised to fight it ; 
among them the now celebrated wash of salt, sulphur, and lime was dis- 
covered as most effective. This wash is still the best known artificial 
remedy for San Jose and kindred scales on deciduous trees; but it is 
impossible with the greatest care to destroy any kind of pest b}^ artificial 
means. There are always solitary trees which will be neglected, careless 
people who refuse to spray, wild shrubbery out of reach of the operators, 
and all of these become sources of infection. While active and efficient 
work was being done by artificial means against this pest, it was discov- 
ered to be disappearing in sections where no spraying was done, and 
investigation showed that one of our native parasites, the Aphelinus fus- 
eipennis, had adapted its taste to it and was rapidly getting it under. 
To-day, wherever the San Jose scale is found we also find its parasite, 
and while the pest has not, and never Avfll disappear, it is entirely con- 
trolled by its little enemy until we pay no further attention to it. 
Spraying is still carried on, however, as it has been found beneficial to 
our fruit trees in killing other pests, i)reventing fungous diseases, 
and keeping the trees healthy: but so far as the San Jose scale is con- 
cerned, there is no further need of artificial remedies. 

This same parasite is generally distributed all over the United States 
and is undoubtedly doing good work, as shown in our quotation from 
Prof. W. G. Johnson of ^lar^dand, but the long winters and compara- 
tively short summers there may check its spread. In the mild winters 
and long summers of California it probably has more broods than there, 
and, increasing in greater quantity, it is enabled to do more effective work. 

Pteromalus puparum. This is a very common enemy of the cabbage 
butterfly (Pieris rapae) in this State, and undoubtedly to its work is 
due the fact that this pest is not more common than it is. This parasite 
has a wide range and is found over the greater part of the United States. 
It is parasitic upon the pupa of the butterfly, upon which it lays a 
number of its eggs, which, hatching out in its unfortunate victim, puts 
an end to its career. Prof. F. M. Webster in "Insect Life" gives an 
interesting account of the operations of this insect, as follows : 

On the morning of August 9tli, we observed a larva of Pieris protodicc, Boisd., in 
the act of transformation to the chrysalis. Near by, and very evidently watching this 
transformation, were a male and female of this parasite. The trio were observed 
several times during the early part of the day, the parasites always on guard, as it 



22 CALIFORNIA STATE HORTICULTURAL COMjMISSION. 

were, although the females several times were observed to attempt oviposition, in 
every case, however, being deterred from so doing by the jerking of the larva, now in 
a semi-pupal state. During one of these visits the male was driven away, but soon 
returned. About 6 p. m., the last observation of the day, the transformation of the 
larva, while not complete, had so far advanced as to prevent the radical movemenis 
which had characterized its sti-uggles during the forenoon, and the female was busily 
engaged in her work of oviposition, the male still present as a spectator ^( ? i . On 
the morning of the 10th, the chrysalis, now fully developed, was removed and placed 
in a glass jar, awaiting further developments. On the morning of the 27th, seventeen 
days after, the adult Ftcromolus were observed issuing from the chrysalis in great 
numbers. After all had emerged, they were counted and found to number «38 males 
and 4 females. The same parasite had been reared from a similar chrysalis on 
August 13th, but the individuals were not counted. 

Comys fusea, HoAvard. (Plate II, Figs. 3, 3a.) This is one of the 
most effective of the scale parasites in our State. Its efforts are princi- 
pally directed to keeping down the brown apricot scale {Eulecanium 
[Lecanmm] armeniacum, Craw) , and wherever it has become thoroughly 
established it has accomplished this object in very good style. The 
brown apricot scale has been one of the most serious scale pests of the 
State, frequently covering the twigs of apricot, plum, and prune trees 
with an almost solid incrustation, destroying the vitality of the trees, 
ruining the fruit, and doing incalculable damage. By means of this 
little internal parasite, however, we are enabled to keep the pest well 
under control, and whenever there is an outbreak of the scale, colonies 
of the parasite are sent and soon become established. The parasites are 
small, and their capture and shipment require great care. The method 
in which this is done is by noting an orchard in which the insects are 
well established the preceding season. From this orchard large quan- 
tities of infested twigs are secured about the middle of May, or before 
the parasites begin to emerge from the scale. These are carefully 
trimmed of all leaves to prevent mildewing, and then placed in square, 
wooden receptacles or boxes, as shown in the illustration (Plate VIII). 
Thase boxes are bored w4th a number of half-inch holes in the upper 
half and all light elsewhere excluded. Into these holes small vials are 
fitted, with the mouths inward. The insects, as -they emerge from the 
scales, seek the light and enter the vials placed to receive them, and 
when there are enough in any one to form a colony of sufficient size, 
usually from twenty-five insects up, the vial is removed, stopped with 
a little cotton wool to prevent their escape and yet admit air, another 
vial is set, and the process is repeated. The vials are then carefully 
packed in stiff paper tubes (see Plate IX) and mailed to all sections 
where there have been any reports of outbreaks of the scale. In this 
manner, beneficial insects are distributed by tens of thousands all over 
the State and nature is aided in her efforts to keep our insect enemies 
within proper limits. 

Eneyrtus flavus, Howard. (Plate IT, Fi^s. 1, la.) This is one of 
several internal parasites of the soft brown scale {Coccus \Lecaninm] 



BUG VS. BUG. 23 

hesperidum) . This scale was another of the very serioiLs pests which the 
orange-growers of California had to contend with and from which they 
have been relieved by insect aids. When orange-growing was in its 
infancy, the soft brown scale obtained a foothold in the orchards, and 
without any check soon spread. In a short time the trees were covered 
with it and were suffering greatly from its depredations. In a compara- 
tively short time, however/ it began to disappear, and investigation 
showed that several internal parasites, among which the Encyrtus flaviis 
was one of the most important, were actively at work upon it. and 
Deducing it below the danger limit. 

Coceophagus lecani. (Plate II, Figs. 2, 2r/.) This is another of the 
internal parasites of the soft brown scale {Coccus hesperidum). It is 
found in several of the Lecaniums, but its best work in this State has 
been on the soft brown scale of the orange, w^hich, in connection with 
Encyrtus flavus, it has kept below^ the danger limit. 

Coeeophoetonus sp. This is an internal parasite of both the yellow 
and red scales, and while it has not done as extensive work as some of 
the other parasites above described, it is none the less an important 
addition to our list of friendly insects. 

Eupelmus mlrabilis, Walsh. This is an egg parasite of the katydid 
{Microcentrim retinervis, Scudder). The female insect lays her eggs 
within those of the katydid. The young parasite is hatched and at 
once proceeds to eat the eggs of the host insect. The Eupelmus mirahilis 
has been an invaluable friend to the orchardists of California and 
especially to those engaged in orange-growing, where at one time the 
katydid was an annoying and destructive pest. It is now rather a rare 
insect in those sections where it was once so common, and it is difficult 
to find its eggs without observing that they have been perforated and 
destroyed by this parasite. 

Besides the above-named insects which are common in California, 
and to which without doubt w^e owe our position as a fruit-producing 
State, there are a number of others of greater or less importance, among 
them a species of Braconid, parasitic on cutworms; Anastatus, an egg- 
parasite of the tent caterpillar, and another parasite of the tent eater- 
pillar eggs. There is also a Tachnid fly which destroys the cabbage 
jjutterfly by laying its eggs on the victim, the young larva hatched 
from which eats up the caterpillar and destroys it. There is also an 
internal parasite of the Eulecanium (Lecanium) rohinarum, Doudas. 
and a species of Aphelinus working as an internal parasite of the aphis. 



24 



CALIFORNIA STATE HORTICrLTURAL COMMISSION. 



DIPTEROUS INSECTS. 

In the great family of dipterous or two-winoed tiies, we find very 
many of our worst pests ; among them the many fruit flies, which do so 
much damage by laying their eggs in the ripening fruit, and which 
hatching out into a mass of crawling maggots render it wholly unfit for 
use; but at the same time this order gives us very many of Cur best 
friends, and prominent among them are the following: 




FIG. 13. Lestophonus icerya, enlarged 



Lestophonus ieerya. (Plate 
I, Figs. 5, 00 ; also Fig. 13.) 
This is an exceedingly small, 
two-winged fly, which was 
found at work on the cottony 
cushion scale at Sidney, N. 
S. W., by Albert Koebele. 
It is now thoroughly estalv 
lished all over California 
wherever the cottony cushion 
scale is found, and has proved 
itself a valuable auxiliary to 
ih'Yrclnliacarrliuali.'^ in keep- 
ing that pest in check. 



Celatopia cpawii, Coquillett. (Fig. 14.) This is another of our 
beneficial flies, being an internal parasite of the well-known twelve- 
spotted squash beetle, so common in fruit-growing districts, and is one 




4-^.V^ 



Larva. 




Female, enlarged. Pupa. 

FIG. 14. Celatoria erawii, Coquillett. 

of the rare instances that have been recorded of a beetle being destroyed 
by the larvae of a fly. It is not only interesting to an entomologist, but is 
of great assistance to the horticulturist in reduiiing the numbers of such 
a serious pest. Mi-. Craw discovered this parasite in the neighborhood 




BUG VS. BUG. 25 

of Los Angeles, where he collected a large number of the beetles, and 
found that fully one third were parasitized. He found them in the 
larval state in the beetles as early as May and as late as the middle of 
October. The May brood pupate early in June and remain in this con- 
dition about two weeks, when they change to the winged form. They 
are numerous in July and August. 

Masieepa pachytyli, Sk. (Fig. 15.) This is one of the Tachnid flies, 
the whole of which family are parasitic on other insects. They are of 
medium size generally, and 

to a casual observer resemble <^^ "\, -jiskL ^ 
our common house flies. The 
favorite food of the greater 
part of the members of the 
family are the caterpillars. 
The female lays her eggs on 
the soft bodies of the caterpil- 
lars and the young grubs de- 
vour their host, which never 
attains its mature state. It 

IS to this family that the re- fig. is. Masicerapachytyll.Sk., parasite of 

duction of moths and butter- the locust, 

flies below the danger limit 

is due. The one of w^hich we give an illustration in Pig. 15 is parasitic 
on the locust, and unquestionably does much toward keeping this terrible 
pest in check in Australia, where it is native. This is one of the intro- 
duced species and has been established in our State. Mr. A. H. Bray 
gives his observations on this insect, as follows : 

The grub, or larva, is found within the locust, where it appears to live upon the 
adipose tissues of the victim, avoiding the vital parts with unfailing instinct. The 
grub lives indifferently in the thoracic region or the abdomen of the locust, and 
frequently three or four may be found in a single grasshopper. 

The grubs leave their victims when they are full gi-own, usually by means of an 
opening which they eat in the side of the locust at the point where the abdomen joins 
the metathorax ; but they do not invariably make their exit from the body of the 
unwilling host at that particular place, as on one occasion I observed two grubs 
escaping from a grasshopper at the same time — one from between the first and 
second abdominal segments, and the other from between the head and prothorax. As 
soon as the grub makes its escape, the grasshopper, which has gradually grown more 
and more feeble as the inclosed parasite has gained in size, dies. In several instances 
I have observed that the grasshopper died before its enemy succeeded in makings 
its escape; and in one case a larva was seen vainly struggling to free itself from 
between the metathorax and the abdomen of a dead grasshopper, where it was 
firmly held by the contracting remains of its victim. The grub, which subsequently 
died without extricating itself, succeeded in freeing more than half its body, but it 
was firmly held by the tail. 

The Sypphidse, or syrphus flies (Figs. 16, 17, and 18), are another 
large family of dipterous insects, many of which are beneflcial to man. 



26 CAIJFORNIA STATE HORTICULTURAL COMMISSION. 

They are usually very conspicuous from size, color, and markings, and 
A^ery manj^ of them resemble other insects and may be mistaken for 
bees, wasps, etc. They are often seen in sunny weather poising almost 
motionless on the wing, especially over flower-beds, occasionally darting 
on their prey. The larva of the syrphus flies is of great benefit in 
destroying all kinds of aphids. It is quite blind, but the egg from which 
it hatches is deposited by the parent fly in the midst of a colony of 
plant aphids, where it gropes about and obtains an abundance of food 
without much trouble. The larva is fleshy, thick and blunt behind, and 
pointed in front. Its mouth is furnished with a triple-pointed dart, 
^vith which it seizas and pierces its prey, and, elevating it as shown in 
the flgure, deliberately sucks it dry. 

MAGNIFIED naTORALSIZE 

N-.AGHinED . , NATURALSIZE 




FKJ Ifi. FIG. 17. 

Larva of Syri)hus Fiy. Pupa of Syrphns Fly. 

This is but a partial list of the very many insect friends which are 
doing so much for California horticulture, and which it has been the 
policy -of the State Board of Horticulture and the State Horticultural 
Commissioner to foster and encourage to the widest extent, and at the 
same time to add to their numbers all beneficial insects which can be 
^secured from any part of the world. To this end correspondence is car- 
ried on with entomologists in different parts of the world, while agents 
oi this department are dispatched to discover and introduce beneficial 
species wherever they can be found. It is the policy of this State to 
use artificial remedies so long as there are no better ones, but to secure, 
introduce, and distribute the better means, and these consist of beneficial 
insects, as soon as possible. In California, at least, this plan has been 
found a, very effective and profitable one, for of all the many insect 
pests which have been found here, and they are as numerous as an.y- 
where on earth, and have been imported from all parts of the earth, 
there are not now more than two or three really serious species, and all 
are controlled by their insect checks, either native or introduced; and 
so far as those for which we have not yet found an effective parasite are 
concerned, we are now searching for one, and in view of our past suc- 
<iess in this line, will undoubtedly find it. 







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